There’s a parameter “How aggressive does an anti-transmission intervention (social distancing, contact-tracing, etc.) have to be to get Re < 1?” (i.e., low enough transmission to stop exponential growth). (Glossary on “R0″ vs “Re”.) This parameter is obviously important and (to my knowledge) still largely unknown.
We do know that doing nothing at all is not sufficient to get Re<1 (obviously). And we also know that what China did in Wuhan is sufficient to get Re<1 (i.e., sometimes welding people into their apartments, deploying 1800 5-person teams of contact-tracers, etc. etc.). So, the answer is somewhere between those two extremes. But I don’t think we have much information about where it is on that interval. At least I don’t know.
So, maybe we can entertain the hopeful theory that if you just post signs encouraging people to wash their hands, that’s all you need! That’s good enough to get Re < 1!! Or the theory that you need to do that and also cancel live sporting events? If it’s something like that, then presumably every community in the world will just do those trivial things (at least, they’ll do it after they get their first rash of cases), and the infection won’t become widespread. I don’t have any good basis for guessing how likely this is.
(Update: See my other answer for a better mental image of what this means.)
There’s a parameter “How aggressive does an anti-transmission intervention (social distancing, contact-tracing, etc.) have to be to get Re < 1?” (i.e., low enough transmission to stop exponential growth). (Glossary on “R0″ vs “Re”.) This parameter is obviously important and (to my knowledge) still largely unknown.
We do know that doing nothing at all is not sufficient to get Re<1 (obviously). And we also know that what China did in Wuhan is sufficient to get Re<1 (i.e., sometimes welding people into their apartments, deploying 1800 5-person teams of contact-tracers, etc. etc.). So, the answer is somewhere between those two extremes. But I don’t think we have much information about where it is on that interval. At least I don’t know.
So, maybe we can entertain the hopeful theory that if you just post signs encouraging people to wash their hands, that’s all you need! That’s good enough to get Re < 1!! Or the theory that you need to do that and also cancel live sporting events? If it’s something like that, then presumably every community in the world will just do those trivial things (at least, they’ll do it after they get their first rash of cases), and the infection won’t become widespread. I don’t have any good basis for guessing how likely this is.
(Update: See my other answer for a better mental image of what this means.)